[Buildroot] [PATCH] u-boot: add option to specify config fragments

[Peter Korsgaard <peter@korsgaard.com>]

U-Boot nowadays also uses kconfig, so we can handle config fragments like we
do for barebox/busybox/linux.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
 boot/uboot/Config.in | 6 ++++++
 boot/uboot/uboot.mk  | 1 +
 2 files changed, 7 insertions(+)

diff --git a/boot/uboot/Config.in b/boot/uboot/Config.in
index 84b7fb42ee..8215912339 100644
--- a/boot/uboot/Config.in
+++ b/boot/uboot/Config.in
@@ -129,6 +129,12 @@ config BR2_TARGET_UBOOT_CUSTOM_CONFIG_FILE
 	depends on BR2_TARGET_UBOOT_USE_CUSTOM_CONFIG
 	help
 	  Path to the U-Boot configuration file.
+
+config BR2_TARGET_UBOOT_CONFIG_FRAGMENT_FILES
+	string "Additional configuration fragment files"
+	help
+	  A space-separated list of configuration fragment files,
+	  that will be merged to the main U-Boot configuration file.
 endif
 
 config BR2_TARGET_UBOOT_NEEDS_DTC
diff --git a/boot/uboot/uboot.mk b/boot/uboot/uboot.mk
index 14a8cc949a..fdacf16856 100644
--- a/boot/uboot/uboot.mk
+++ b/boot/uboot/uboot.mk
@@ -196,6 +196,7 @@ else ifeq ($(BR2_TARGET_UBOOT_USE_CUSTOM_CONFIG),y)
 UBOOT_KCONFIG_FILE = $(call qstrip,$(BR2_TARGET_UBOOT_CUSTOM_CONFIG_FILE))
 endif # BR2_TARGET_UBOOT_USE_DEFCONFIG
 
+UBOOT_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_TARGET_UBOOT_CONFIG_FRAGMENT_FILES))
 UBOOT_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
 UBOOT_KCONFIG_OPTS = $(UBOOT_MAKE_OPTS)
 define UBOOT_HELP_CMDS
-- 
2.11.0